1. Field of the Invention
The present invention relates to a mechanical key which mechanically locks and unlocks a locking/unlocking device by inserting a key plate into a key cylinder of the locking/unlocking device for operation, and a locking/unlocking key having the mechanical key.
2. Description of the Related Art
Japanese Patent Application Laid-Open (JP-A) No. 2004-218371 describes a locking/unlocking system constructed such that when a driver carries a locking/unlocking key and approaches the door of a driver's seat, mutual communication is done between a portable device of the locking/unlocking key and a vehicle, and upon establishment of the mutual communication, a door lock as a locking/unlocking device is unlocked.
In the above locking/unlocking system, when the driver moves away from the vehicle, mutual communication between the portable device and the vehicle is unestablished so that the door is locked. The driver can lock and unlock the door without touching the vehicle. The convenience for a driver can be improved.
An emergency mechanical key is housed in the portable device of the locking/unlocking key used for this locking/unlocking system in case that mutual communication between the portable device and the vehicle cannot be done due to failure or battery exhaustion of the portable device (see Japanese Patent Application Laid-Open (JP-A) No. 2005-290905).
When the locking/unlocking operation by mutual communication of the portable device cannot be done, the driver inserts a key plate of the mechanical key into a key cylinder provided in a door for turning operation and can mechanically lock and unlock a door.
The emergency mechanical key is required to be housed in the portable device. The size (length) of the locking/unlocking key depends on the length in the longitudinal direction of the mechanical key. In this regard, the design of the portable device is limited. The locking/unlocking key is hard to be made thinner and smaller thereby, the portability thereof is not good.
A mechanical key which is singly used without being housed in the portable device is also required to be made thinner and smaller to improve the portability.